feat(tvix/eval): track pattern binding names r/7448

These need to be preserved at least for builtins.toXML.

Also, we incorrectly only wrote an <attrspat> in case ellipsis was true,
but that's not the case.

Change-Id: I6bff9c47c2922f878d5c43e48280cda9c9ddb692
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10686
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: aspen <root@gws.fyi>

1 files changed, 21 insertions, 0 deletions

diff --git a/tvix/eval/src/tests/nix_tests/eval-okay-xml.nix b/tvix/eval/src/tests/nix_tests/eval-okay-xml.nix
new file mode 100644
index 0000000000..9ee9f8a0b4
--- /dev/null
+++ b/tvix/eval/src/tests/nix_tests/eval-okay-xml.nix
@@ -0,0 +1,21 @@
+rec {
+
+  x = 123;
+
+  y = 567.890;
+
+  a = "foo";
+
+  b = "bar";
+
+  c = "foo" + "bar";
+
+  f = {z, x, y}: if y then x else z;
+
+  id = x: x;
+
+  at = args@{x, y, z}: x;
+
+  ellipsis = {x, y, z, ...}: x;
+
+}